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Do/While Loop


ComputerColumbus
Go to solution Solved by Ch0cu3r,

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Hi,

 

I'm learning PHP on CodeAcademy and for one of the lessons, I'm supposed to create my very own do/while loop. Here it is:

 

<?php
       $red = exciting;
         do {
              echo "<p>It's $red to be red.</p>";
       } while ($red == exciting);
    ?>

 

Not sure why it's not going through. It keeps giving me an error. Can you please help?

 

Best regards, ComputerColumbus :pirate:

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You're getting an undefined constant error because php assumes exciting would be a constant. If you want to check if $red is equal to the sting of exciting you can either wrap it in single or double quotes.

<?php
       $red = exciting;
         do {
              echo "<p>It's $red to be red.</p>";
       } while ($red == "exciting");
    ?>
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The loop you wrote is an infinite or endless loop because the loop will continue indefinitely as the conditional value never changes.

Add some way for $red to change so the condition will eventually equate to false and the loop will terminate.

<?php
error_reporting(E_ALL);
ini_set('display_errors',1);

$red = "exciting";

$feelings = array(
'exciting',
'exciting',
'boring',
'exciting'
);

// use do-while loop when you want the code to
// run at least 1 time prior to checking the condition
do 
{
    // run statements
    echo "<p>It's $red to be red.</p>";
    
    // get value of $red
    $red = $feelings[rand(0,3)];
    
  // check condition  
} while ($red == 'exciting');
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  • Solution

I tried adding at the bottom: $red = false; It's supposed to stop the loop, right? It still doesn't work.

Where did you add that line? It must be within the do {} statement not after the while condition.

$red = "exciting";
do {
    echo "<p>It's $red to be red.</p>";
    $red = false; // set $red to false to stop the loop
} while ($red == "exciting");
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1 <!DOCTYPE html>
2 <html>
3  <head>
4        <title>Your own do-while</title>
5       <link type='text/css' rel='stylesheet' href='style.css'/>
6   </head>
7   <body>
8       //write your do-while loop below
9      <?p
10     $red = "exciting";
11      do {
12         echo "<p>It's $red to be red.</p>";
13         $red = false;
14    } while ($red = "exciting");
15   ?>
16   </body>0
17  </html>

 

This is the error message that it gives me: Parse error: syntax error, unexpected T_VARIABLE on line 10

Edited by ComputerColumbus
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On line 9 you have an incomplete php tag, it should be <?php

 

Also on line 14 you need to use the comparison operator == not the assignment operator = 

    } while ($red == "exciting");
//                ^
//    needs to be the comparison operator

If used the assignment operator you will end up with an infinite loop.

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